new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/sound/sound_firmware.c b/sound/sound_firmware.c
index 37711a5..e149034 100644
--- a/sound/sound_firmware.c
+++ b/sound/sound_firmware.c
@@ -19,7 +19,7 @@
 		printk(KERN_INFO "Unable to load '%s'.\n", fn);
 		return 0;
 	}
-	l = i_size_read(filp->f_path.dentry->d_inode);
+	l = i_size_read(file_inode(filp));
 	if (l <= 0 || l > 131072)
 	{
 		printk(KERN_INFO "Invalid firmware '%s'\n", fn);